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Polarity- and Intensity-Independent Modulation of Timing During Delay Eyeblink Conditioning Using Cerebellar Transcranial Direct Current Stimulation. THE CEREBELLUM 2021; 19:383-391. [PMID: 32036562 DOI: 10.1007/s12311-020-01114-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Delay eyeblink conditioning (dEBC) is widely used to assess cerebellar-dependent associative motor learning, including precise timing processes. Transcranial direct current stimulation (tDCS), noninvasive brain stimulation used to indirectly excite and inhibit select brain regions, may be a promising tool for understanding how functional integrity of the cerebellum influences dEBC behavior. The aim of this study was to assess whether tDCS-induced inhibition (cathodal) and excitation (anodal) of the cerebellum differentially impact timing of dEBC. A standard 10-block dEBC paradigm was administered to 102 healthy participants. Participants were randomized to stimulation conditions in a double-blind, between-subjects sham-controlled design. Participants received 20-min active (anodal or cathodal) stimulation at 1.5 mA (n = 20 anodal, n = 22 cathodal) or 2 mA (n = 19 anodal, n = 21 cathodal) or sham stimulation (n = 20) concurrently with dEBC training. Stimulation intensity and polarity effects on percent conditioned responses (CRs) and CR peak and onset latency were examined using repeated-measures analyses of variance. Acquisition of CRs increased over time at a similar rate across sham and all active stimulation groups. CR peak and onset latencies were later, i.e., closer to air puff onset, in all active stimulation groups compared to the sham group. Thus, tDCS facilitated cerebellar-dependent timing of dEBC, irrespective of stimulation intensity and polarity. These findings highlight the feasibility of using tDCS to modify cerebellar-dependent functions and provide further support for cerebellar contributions to human eyeblink conditioning and for exploring therapeutic tDCS interventions for cerebellar dysfunction.
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152
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Visual Attention Modulates Glutamate-Glutamine Levels in Vestibular Cortex: Evidence from Magnetic Resonance Spectroscopy. J Neurosci 2021; 41:1970-1981. [PMID: 33452222 DOI: 10.1523/jneurosci.2018-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 11/12/2020] [Accepted: 12/22/2020] [Indexed: 11/21/2022] Open
Abstract
Attending to a stimulus enhances the neuronal responses to it, while responses to nonattended stimuli are not enhanced and may even be suppressed. Although the neural mechanisms of response enhancement for attended stimuli have been intensely studied, the neural mechanisms underlying attentional suppression remain largely unknown. It is uncertain whether attention acts to suppress the processing in sensory cortical areas that would otherwise process the nonattended stimulus or the subcortical input to these cortical areas. Moreover, the neurochemical mechanisms inducing a reduction or suppression of neuronal responses to nonattended stimuli are as yet unknown. Here, we investigated how attention directed toward visual processing cross-modally acts to suppress vestibular responses in the human brain. By using functional magnetic resonance spectroscopy in a group of female and male subjects, we find that attention to visual motion downregulates in a load-dependent manner the concentration of excitatory neurotransmitter (glutamate and its precursor glutamine, referred to together as Glx) within the parietoinsular vestibular cortex (PIVC), a core cortical area of the vestibular system, while leaving the concentration of inhibitory neurotransmitter (GABA) in PIVC unchanged. This makes PIVC less responsive to excitatory thalamic vestibular input, as corroborated by functional magnetic resonance imaging. Together, our results suggest that attention acts to suppress the processing of nonattended sensory cues cortically by neurochemically rendering the core cortical area of the nonattended sensory modality less responsive to excitatory thalamic input.SIGNIFICANCE STATEMENT Here, we address a fundamental problem that has eluded attention research for decades, namely, how the brain ignores irrelevant stimuli. To date, three classes of solutions to this problem have been proposed: (1) enhancement of GABAergic interneuron activity in cortex, (2) downregulation of glutamatergic cell activity in cortex; and (3) downregulation of neural activity in thalamic projection areas, which would then provide the cortex with less input. Here, we use magnetic resonance spectroscopy in humans and find support for the second hypothesis, implying that attention to one sensory modality involves the suppression of irrelevant stimuli of another sensory modality by downregulating glutamate in the cortex.
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153
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Choi CH, Iordanishvili E, Shah NJ, Binkofski F. Magnetic resonance spectroscopy with transcranial direct current stimulation to explore the underlying biochemical and physiological mechanism of the human brain: A systematic review. Hum Brain Mapp 2021; 42:2642-2671. [PMID: 33634527 PMCID: PMC8090777 DOI: 10.1002/hbm.25388] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/29/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
A large body of molecular and neurophysiological evidence connects synaptic plasticity to specific functions and energy metabolism in particular areas of the brain. Furthermore, altered plasticity and energy regulation has been associated with a number of neuropsychiatric disorders. A favourable approach enabling the modulation of neuronal excitability and energy in humans is to stimulate the brain using transcranial direct current stimulation (tDCS) and then to observe the effect on neurometabolites using magnetic resonance spectroscopy (MRS). In this way, a well-defined modulation of brain energy and excitability can be achieved using a dedicated tDCS protocol to a predetermined brain region. This systematic review was guided by the preferred reporting items for systematic reviews and meta-analysis and summarises recent literature studying the effect of tDCS on neurometabolites in the human brain as measured by proton or phosphorus MRS. Limitations and recommendations are discussed for future research. The findings of this review provide clear evidence for the potential of using tDCS and MRS to examine and understand the effect of neurometabolites in the in vivo human brain.
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Affiliation(s)
- Chang-Hoon Choi
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich, Jülich, Germany
| | - Elene Iordanishvili
- Division of Clinical Cognitive Sciences, Department of Neurology, RWTH Aachen University Hospital, Aachen, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich, Jülich, Germany.,Institute of Neuroscience and Medicine - 11, JARA, Forschungszentrum Jülich, Jülich, Germany.,JARA - BRAIN - Translational Medicine, Aachen, Germany.,Department of Neurology, RWTH Aachen University, Aachen, Germany
| | - Ferdinand Binkofski
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich, Jülich, Germany.,Division of Clinical Cognitive Sciences, Department of Neurology, RWTH Aachen University Hospital, Aachen, Germany.,JARA - BRAIN - Translational Medicine, Aachen, Germany
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154
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Pollok B, Schmitz-Justen C, Krause V. Cathodal Transcranial Direct Current Stimulation (tDCS) Applied to the Left Premotor Cortex Interferes with Explicit Reproduction of a Motor Sequence. Brain Sci 2021; 11:207. [PMID: 33572164 PMCID: PMC7914983 DOI: 10.3390/brainsci11020207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 11/17/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that allows the modulation of cortical excitability. TDCS effects can outlast the stimulation period presumably due to changes of GABA concentration which play a critical role in use-dependent plasticity. Consequently, tDCS and learning-related synaptic plasticity are assumed to share common mechanisms. Motor sequence learning has been related to activation changes within a cortico-subcortical network and findings from a meta-analysis point towards a core network comprising the cerebellum as well as the primary motor (M1) and the dorsolateral premotor cortex (dPMC). The latter has been particularly related to explicit motor learning by means of brain imaging techniques. We here test whether tDCS applied to the left dPMC affects the acquisition and reproduction of an explicitly learned motor sequence. To this end, 18 healthy volunteers received anodal, cathodal and sham tDCS to the left dPMC and were then trained on a serial reaction time task (SRTT) with their right hand. Immediately after the training and after overnight sleep, reproduction of the learned sequence was tested by means of reaction times as well as explicit recall. Regression analyses suggest that following cathodal tDCS reaction times at the end of the SRTT training-block explained a significant proportion of the number of correctly reported sequence items after overnight sleep. The present data suggest the left premotor cortex as one possible target for the application of non-invasive brain stimulation techniques in explicit motor sequence learning with the right hand.
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Affiliation(s)
- Bettina Pollok
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University Duesseldorf, 40225 Duesseldorf, Germany; (C.S.-J.); (V.K.)
| | - Claire Schmitz-Justen
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University Duesseldorf, 40225 Duesseldorf, Germany; (C.S.-J.); (V.K.)
| | - Vanessa Krause
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University Duesseldorf, 40225 Duesseldorf, Germany; (C.S.-J.); (V.K.)
- Department of Neuropsychology, Mauritius Hospital and Neurorehabilitation Center Meerbusch, 40670 Meerbusch, Germany
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155
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Visual cortex cTBS increases mixed percept duration while a-tDCS has no effect on binocular rivalry. PLoS One 2021; 16:e0239349. [PMID: 33539443 PMCID: PMC7861428 DOI: 10.1371/journal.pone.0239349] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/19/2020] [Indexed: 11/29/2022] Open
Abstract
Neuromodulation of the primary visual cortex using anodal transcranial direct current stimulation (a-tDCS) can alter visual perception and enhance neuroplasticity. However, the mechanisms that underpin these effects are currently unknown. When applied to the motor cortex, a-tDCS reduces the concentration of the inhibitory neurotransmitter gamma aminobutyric acid (GABA), an effect that has been linked to increased neuroplasticity. The aim of this study was to assess whether a-tDCS also reduces GABA-mediated inhibition when applied to the human visual cortex. Changes in visual cortex inhibition were measured using the mixed percept duration in binocular rivalry. Binocular rivalry mixed percept duration has recently been advocated as a direct and sensitive measure of visual cortex inhibition whereby GABA agonists decrease mixed percept durations and agonists of the excitatory neurotransmitter acetylcholine (ACH) increase them. Our hypothesis was that visual cortex a-tDCS would increase mixed percept duration by reducing GABA-mediated inhibition and increasing cortical excitation. In addition, we measured the effect of continuous theta-burst transcranial magnetic stimulation (cTBS) of the visual cortex on binocular rivalry dynamics. When applied to the motor or visual cortex, cTBS increases GABA concentration and we therefore hypothesized that visual cortex cTBS would decrease the mixed percept duration. Binocular rivalry dynamics were recorded before and after active and sham a-tDCS (N = 15) or cTBS (N = 15). Contrary to our hypotheses, a-tDCS had no effect, whereas cTBS increased mixed percepts during rivalry. These results suggest that the neurochemical mechanisms of a-tDCS may differ between the motor and visual cortices.
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156
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Sánchez-León CA, Cordones I, Ammann C, Ausín JM, Gómez-Climent MA, Carretero-Guillén A, Sánchez-Garrido Campos G, Gruart A, Delgado-García JM, Cheron G, Medina JF, Márquez-Ruiz J. Immediate and after effects of transcranial direct-current stimulation in the mouse primary somatosensory cortex. Sci Rep 2021; 11:3123. [PMID: 33542338 PMCID: PMC7862679 DOI: 10.1038/s41598-021-82364-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/24/2020] [Indexed: 01/30/2023] Open
Abstract
Transcranial direct-current stimulation (tDCS) is a non-invasive brain stimulation technique consisting in the application of weak electric currents on the scalp. Although previous studies have demonstrated the clinical value of tDCS for modulating sensory, motor, and cognitive functions, there are still huge gaps in the knowledge of the underlying physiological mechanisms. To define the immediate impact as well as the after effects of tDCS on sensory processing, we first performed electrophysiological recordings in primary somatosensory cortex (S1) of alert mice during and after administration of S1-tDCS, and followed up with immunohistochemical analysis of the stimulated brain regions. During the application of cathodal and anodal transcranial currents we observed polarity-specific bidirectional changes in the N1 component of the sensory-evoked potentials (SEPs) and associated gamma oscillations. On the other hand, 20 min of cathodal stimulation produced significant after-effects including a decreased SEP amplitude for up to 30 min, a power reduction in the 20-80 Hz range and a decrease in gamma event related synchronization (ERS). In contrast, no significant changes in SEP amplitude or power analysis were observed after anodal stimulation except for a significant increase in gamma ERS after tDCS cessation. The polarity-specific differences of these after effects were corroborated by immunohistochemical analysis, which revealed an unbalance of GAD 65-67 immunoreactivity between the stimulated versus non-stimulated S1 region only after cathodal tDCS. These results highlight the differences between immediate and after effects of tDCS, as well as the asymmetric after effects induced by anodal and cathodal stimulation.
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Affiliation(s)
- Carlos A. Sánchez-León
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - Isabel Cordones
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - Claudia Ammann
- grid.428486.40000 0004 5894 9315HM CINAC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain
| | - José M. Ausín
- grid.157927.f0000 0004 1770 5832Instituto de Investigación E Innovación en Bioingeniería, Universidad Politécnica de Valencia, Valencia, Spain
| | - María A. Gómez-Climent
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - Alejandro Carretero-Guillén
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - Guillermo Sánchez-Garrido Campos
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - Agnès Gruart
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - José M. Delgado-García
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
| | - Guy Cheron
- grid.8364.90000 0001 2184 581XLaboratory of Electrophysiology, Université de Mons, Mons, Belgium ,grid.4989.c0000 0001 2348 0746Laboratory of Neurophysiology and Movement Biomechanics, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Javier F. Medina
- grid.39382.330000 0001 2160 926XDepartment of Neuroscience, Baylor College of Medicine, Houston, TX USA
| | - Javier Márquez-Ruiz
- grid.15449.3d0000 0001 2200 2355Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013 Seville, Spain
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157
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Yamada Y, Sumiyoshi T. Neurobiological Mechanisms of Transcranial Direct Current Stimulation for Psychiatric Disorders; Neurophysiological, Chemical, and Anatomical Considerations. Front Hum Neurosci 2021; 15:631838. [PMID: 33613218 PMCID: PMC7890188 DOI: 10.3389/fnhum.2021.631838] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 01/11/2021] [Indexed: 12/23/2022] Open
Abstract
Backgrounds: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique for the treatment of several psychiatric disorders, e.g., mood disorders and schizophrenia. Therapeutic effects of tDCS are suggested to be produced by bi-directional changes in cortical activities, i.e., increased/decreased cortical excitability via anodal/cathodal stimulation. Although tDCS provides a promising approach for the treatment of psychiatric disorders, its neurobiological mechanisms remain to be explored. Objectives: To review recent findings from neurophysiological, chemical, and brain-network studies, and consider how tDCS ameliorates psychiatric conditions. Findings: Enhancement of excitatory synaptic transmissions through anodal tDCS stimulation is likely to facilitate glutamate transmission and suppress gamma-aminobutyric acid transmission in the cortex. On the other hand, it positively or negatively modulates the activities of dopamine, serotonin, and acetylcholine transmissions in the central nervous system. These neural events by tDCS may change the balance between excitatory and inhibitory inputs. Specifically, multi-session tDCS is thought to promote/regulate information processing efficiency in the cerebral cortical circuit, which induces long-term potentiation (LTP) by synthesizing various proteins. Conclusions: This review will help understand putative mechanisms underlying the clinical benefits of tDCS from the perspective of neurotransmitters, network dynamics, intracellular events, and related modalities of the brain function.
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Affiliation(s)
- Yuji Yamada
- Department of Psychiatry, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Tomiki Sumiyoshi
- Department of Preventive Intervention for Psychiatric Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan
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158
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Pavlova EL, Menshikova AA, Akzhigitov RG, B Guekht A. [Transcranial direct current stimulation in neurology and psychiatry]. Zh Nevrol Psikhiatr Im S S Korsakova 2021; 120:123-130. [PMID: 33459552 DOI: 10.17116/jnevro2020120121123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive method of modulating brain excitability by low intensity direct current. At present, there are numerous studies of tDCS application in various mental and neurological diseases. In this review, the data of tDCS efficiency in the treatment of different disorders are presented and the recommendations on using this method in clinical practice are given.
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Affiliation(s)
| | - A A Menshikova
- Soloviev Scientific and Practical Psychoneurological Center, Moscow, Russia
| | - R G Akzhigitov
- Soloviev Scientific and Practical Psychoneurological Center, Moscow, Russia
| | - A B Guekht
- Soloviev Scientific and Practical Psychoneurological Center, Moscow, Russia.,Pirogov Russian National Research Medical University, Moscow, Russia
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159
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Preliminary effects of prefrontal tDCS on dopamine-mediated behavior and psychophysiology. Behav Brain Res 2021; 402:113091. [PMID: 33359843 DOI: 10.1016/j.bbr.2020.113091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 11/23/2022]
Abstract
The ability to manipulate dopamine in vivo through non-invasive, reversible mechanisms has the potential to impact clinical, translational, and basic research. Recent PET studies have demonstrated increased dopamine release in the striatum after bifrontal transcranial direct current stimulation (tDCS). We sought to extend this work by examining whether bifrontal tDCS could demonstrate an effect on behavioral and physiological correlates of subcortical dopamine activity. We conducted a preliminary between-subjects study (n = 30) with active and sham tDCS and used spontaneous eye blink rate (EBR), facial attractiveness ratings, and greyscales orienting bias as indirect proxies for dopamine functioning. The initial design and analyses were pre-registered (https://osf.io/gmnpc). Stimulation did not significantly affect any of the three measures, though effect sizes were often moderately large and were all in the predicted directions. Additional exploratory analyses suggested that stimulation's effect on EBR might depend on pre-stimulation dopamine levels. Our results suggest that larger samples than those that are standard in tDCS literature should be used to assess the effect of tDCS on dopamine using indirect measures. Further, exploratory results add to a growing body of work demonstrating the importance of accounting for individual differences in tDCS response.
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160
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Transcranial direct current stimulation of the posterior parietal cortex biases human hand choice. Sci Rep 2021; 11:204. [PMID: 33420316 PMCID: PMC7794501 DOI: 10.1038/s41598-020-80611-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 12/23/2020] [Indexed: 11/08/2022] Open
Abstract
Hand choices—deciding which hand to use to reach for targets—represent continuous, daily, unconscious decisions. The posterior parietal cortex (PPC) contralateral to the selected hand is activated during a hand-choice task, and disruption of left PPC activity with a single-pulse transcranial magnetic stimulation prior to the execution of the motion suppresses the choice to use the right hand but not vice versa. These findings imply the involvement of either bilateral or left PPC in hand choice. To determine whether the effects of PPC’s activity are essential and/or symmetrical in hand choice, we increased or decreased PPC excitability in 16 healthy participants using transcranial direct current stimulation (tDCS; 10 min, 2 mA, 5 × 7 cm) and examined its online and residual effects on hand-choice probability and reaction time. After the right PPC was stimulated with an anode and the left PPC with a cathode, the probability of left-hand choice significantly increased and reaction time significantly decreased. However, no significant changes were observed with the stimulation of the right PPC with a cathode and the left PPC with an anode. These findings, thus, reveal the asymmetry of PPC-mediated regulation in hand choice.
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161
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Azarpaikan A, Taherii Torbati HR, Sohrabi M, Boostani R, Ghoshuni M. The Effect of Parietal and Cerebellar Transcranial Direct Current Stimulation on Bimanual Coordinated Adaptive Motor Learning. J PSYCHOPHYSIOL 2021. [DOI: 10.1027/0269-8803/a000254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract. Many daily activities, such as typing, eating, playing the piano, and passing the ball in volleyball, require the proficient coordination of both hands. In this study, the effects of anodal transcranial direct current stimulation (atDCS) on the acquisition, retention, and transfer of bimanual adaptive motor tasks were investigated. To this end, 64 volunteers ( Mage = 24.36 years; SD = 2.51; 16 females) participated in this double-blind study and were categorized randomly into 4 groups. During the pretest, posttest, 24-h and 48-h retention, and transfer tests, two forms of bimanual coordination (BC) of the Vienna test system were performed. Between the pretest and posttest, all participants were trained in a bimanual coordination adaptive task with concurrent brain stimulation (1.5 mA for 15 min) for two consecutive days. The first experimental group (parietal-stim) received atDCS over the right parietal cortex (P4), while the second experimental group (cerebellar-stim) received atDCS over the bilateral cerebellum (2.5 cm bilateral to the inion). The third group (sham) received a sham stimulation. Finally, the control group did not receive any stimulation at all (control). Repeated-measure analysis of variance (ANOVARM) results indicated that parietal tDCS affected motor performance in the posttest, while overall mean duration and overall error mean duration of movement decreased. The results also revealed a significant impact of cerebellar tDCS on the posttest, 24-h and 48-h retention, and transfer tests. The overall mean duration and overall error mean durations of movement in this group were significantly lower than those in the other groups. Accordingly, we found evidence that atDCS over the cerebellum leads to more improvement in motor performance and transfer in a bimanual coordination task than atDCS over the right parietal. Finally, these results point to the possibly beneficial application of atDCS for learning and recovery of bimanual motor skills, especially when subjects are faced with a new challenging situation.
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Affiliation(s)
- Atefeh Azarpaikan
- Department of Motor Behavior, Faculty of Physical Education and Sport Science, Ferdowsi University of Mashhad, Iran
| | - Hamid Reza Taherii Torbati
- Department of Motor Behavior, Faculty of Physical Education and Sport Science, Ferdowsi University of Mashhad, Iran
| | - Mehdi Sohrabi
- Department of Motor Behavior, Faculty of Physical Education and Sport Science, Ferdowsi University of Mashhad, Iran
| | - Reza Boostani
- Department of Neurology, Mashhad University of Medical sciences, Mashhad, Iran
| | - Majid Ghoshuni
- Department of Biomedical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran
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162
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Effects of bifrontal transcranial direct current stimulation on brain glutamate levels and resting state connectivity: multimodal MRI data for the cathodal stimulation site. Eur Arch Psychiatry Clin Neurosci 2021; 271:111-122. [PMID: 32743758 PMCID: PMC7867555 DOI: 10.1007/s00406-020-01177-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/22/2020] [Indexed: 12/21/2022]
Abstract
Transcranial direct current stimulation (tDCS) over prefrontal cortex (PFC) regions is currently proposed as therapeutic intervention for major depression and other psychiatric disorders. The in-depth mechanistic understanding of this bipolar and non-focal stimulation technique is still incomplete. In a pilot study, we investigated the effects of bifrontal stimulation on brain metabolite levels and resting state connectivity under the cathode using multiparametric MRI techniques and computational tDCS modeling. Within a double-blind cross-over design, 20 subjects (12 women, 23.7 ± 2 years) were randomized to active tDCS with standard bifrontal montage with the anode over the left dorsolateral prefrontal cortex (DLPFC) and the cathode over the right DLPFC. Magnetic resonance spectroscopy (MRS) was acquired before, during, and after prefrontal tDCS to quantify glutamate (Glu), Glu + glutamine (Glx) and gamma aminobutyric acid (GABA) concentration in these areas. Resting-state functional connectivity MRI (rsfcMRI) was acquired before and after the stimulation. The individual distribution of tDCS induced electric fields (efields) within the MRS voxel was computationally modelled using SimNIBS 2.0. There were no significant changes of Glu, Glx and GABA levels across conditions but marked differences in the course of Glu levels between female and male participants were observed. Further investigation yielded a significantly stronger Glu reduction after active compared to sham stimulation in female participants, but not in male participants. For rsfcMRI neither significant changes nor correlations with MRS data were observed. Exploratory analyses of the effect of efield intensity distribution on Glu changes showed distinct effects in different efield groups. Our findings are limited by the small sample size, but correspond to previously published results of cathodal tDCS. Future studies should address gender and efield intensity as moderators of tDCS induced effects.
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163
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Sánchez-León CA, Sánchez-López Á, Gómez-Climent MA, Cordones I, Cohen Kadosh R, Márquez-Ruiz J. Impact of chronic transcranial random noise stimulation (tRNS) on GABAergic and glutamatergic activity markers in the prefrontal cortex of juvenile mice. PROGRESS IN BRAIN RESEARCH 2021; 264:323-341. [PMID: 34167661 DOI: 10.1016/bs.pbr.2021.01.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Transcranial random noise stimulation (tRNS), a non-invasive neuromodulatory technique capable of altering cortical activity, has been proposed to improve the signal-to-noise ratio at the neuronal level and the sensitivity of the neurons following an inverted U-function. The aim of this study was to examine the effects of tRNS on vGLUT1 and GAD 65-67 and its safety in terms of pathological changes. For that, juvenile mice were randomly distributed in three different groups: "tRNS 1×" receiving tRNS at the density current used in humans (0.3A/m2, 20min), "tRNS 100×" receiving tRNS at two orders of magnitude higher (30.0A/m2, 20min) and "sham" (0.3A/m2, 15s). Nine tRNS sessions during 5 weeks were administered to the prefrontal cortex of awake animals. No detectable tissue macroscopic lesions were observed after tRNS sessions. Post-stimulation immunohistochemical analysis of GAD 65-67 and vGLUT1 immunoreactivity showed reduced GAD 65-67 immunoreactivity levels in the region directly beneath the electrode for tRNS 1× group with no significant effects in the tRNS 100× nor sham group. The observed results suggest an excitatory effect associated with a decrease in GABA levels in absence of major histopathological alterations providing a novel mechanistic explanation for tRNS effects.
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Affiliation(s)
- Carlos A Sánchez-León
- Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Seville, Spain
| | - Álvaro Sánchez-López
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - María A Gómez-Climent
- Educational Psychology and Psychobiology Area, Faculty of Education, International University of La Rioja, Logroño, Spain
| | - Isabel Cordones
- Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Seville, Spain
| | - Roi Cohen Kadosh
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Javier Márquez-Ruiz
- Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Seville, Spain.
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Habich A, Fehér KD, Antonenko D, Boraxbekk CJ, Flöel A, Nissen C, Siebner HR, Thielscher A, Klöppel S. Stimulating aged brains with transcranial direct current stimulation: Opportunities and challenges. Psychiatry Res Neuroimaging 2020; 306:111179. [PMID: 32972813 DOI: 10.1016/j.pscychresns.2020.111179] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/30/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023]
Abstract
Ageing involves significant neurophysiological changes that are both systematic while at the same time exhibiting divergent trajectories across individuals. These changes underlie cognitive impairments in elderly while also affecting the response of aged brains to interventions like transcranial direct current stimulation (tDCS). While the cognitive benefits of tDCS are more variable in elderly, older adults also respond differently to stimulation protocols compared to young adults. The age-related neurophysiological changes influencing the responsiveness to tDCS remain to be addressed in-depth. We review and discuss the premise that, in comparison to the better calibrated brain networks present in young adults, aged systems perform further away from a homoeostatic set-point. We argue that this age-related neurophysiological deviation from the homoeostatic optimum extends the leeway for tDCS to modulate the aged brain. This promotes the potency of immediate tDCS effects to induce directional plastic changes towards the homoeostatic equilibrium despite the impaired plasticity induction in elderly. We also consider how age-related neurophysiological changes pose specific challenges for tDCS that necessitate proper adaptations of stimulation protocols. Appreciating the distinctive properties of aged brains and the accompanying adjustment of stimulation parameters can increase the potency and reliability of tDCS as a treatment avenue in older adults.
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Affiliation(s)
- Annegret Habich
- University Hospital of Old Age Psychiatry and Psychotherpa, University of Bern, Bolligenstrasse 111, 3000 Bern, Switzerland; Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany.
| | - Kristoffer D Fehér
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bolligenstrasse 111, 3000 Bern, Switzerland
| | - Daria Antonenko
- Department of Neurology, University of Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - Carl-Johan Boraxbekk
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Østvej, 2650 Hvidovre, Denmark; Department of Radiation Sciences, Umeå University, 90187 Umeå, Sweden; Institute of Sports Medicine Copenhagen (ISMC), Copenhagen University Hospital Bispebjerg, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark
| | - Agnes Flöel
- Department of Neurology, University of Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany; German Center for Neurodegenerative Diseases, Ellernholzstraße 1-2, 17489 Greifswald, Germany
| | - Christoph Nissen
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bolligenstrasse 111, 3000 Bern, Switzerland; Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Freiburg, Hauptstraße 5, 79104 Freiburg, Germany
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Østvej, 2650 Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark; Institute for Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Nørre Allé 20, 2200 Copenhagen, Denmark
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Østvej, 2650 Hvidovre, Denmark; Department of Electrical Engineering, Technical University of Denmark, Ørsteds Pl. 348, 2800 Kgs. Lyngby, Denmark
| | - Stefan Klöppel
- University Hospital of Old Age Psychiatry and Psychotherpa, University of Bern, Bolligenstrasse 111, 3000 Bern, Switzerland
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165
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Jeong H, Oh JK, Choi EK, Im JJ, Yoon S, Knotkova H, Bikson M, Song IU, Lee SH, Chung YA. Effects of transcranial direct current stimulation on addictive behavior and brain glucose metabolism in problematic online gamers. J Behav Addict 2020; 9:1011-1021. [PMID: 33361487 PMCID: PMC8969730 DOI: 10.1556/2006.2020.00092] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 08/11/2020] [Accepted: 10/30/2020] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND AND AIMS Some online gamers may encounter difficulties in controlling their gaming behavior. Previous studies have demonstrated beneficial effects of transcranial direct current stimulation (tDCS) on various kinds of addiction. This study investigated the effects of tDCS on addictive behavior and regional cerebral metabolic rate of glucose (rCMRglu) in problematic online gamers. METHODS Problematic online gamers were randomized and received 12 sessions of either active (n = 13) or sham tDCS (n = 13) to the dorsolateral prefrontal cortex over 4 weeks (anode F3/cathode F4, 2 mA for 30 min, 3 sessions per week). Participants underwent brain 18F-fluoro-2-deoxyglucose positron emission tomography scans and completed questionnaires including the Internet Addiction Test (IAT), Brief Self-Control Scale (BSCS), and Behavioral Inhibition System/Behavioral Activation System scales (BIS/BAS) at the baseline and 4-week follow-up. RESULTS Significant decreases in time spent on gaming (P = 0.005), BIS (P = 0.03), BAS-fun seeking (P = 0.04), and BAS-reward responsiveness (P = 0.01), and increases in BSCS (P = 0.03) were found in the active tDCS group, while decreases in IAT were shown in both groups (P < 0.001). Group-by-time interaction effects were not significant for these measures. Increases in BSCS scores were correlated with decreases in IAT scores in the active group (β = -0.85, P < 0.001). rCMRglu in the left putamen, pallidum, and insula was increased in the active group compared to the sham group (P for interaction < 0.001). DISCUSSION AND CONCLUSIONS tDCS may be beneficial for problematic online gaming potentially through changes in self-control, motivation, and striatal/insular metabolism. Further larger studies with longer follow-up period are warranted to confirm our findings.
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Affiliation(s)
- Hyeonseok Jeong
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea,Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jin Kyoung Oh
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Eun Kyoung Choi
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jooyeon Jamie Im
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Sujung Yoon
- Department of Brain and Cognitive Sciences and Ewha Brain Institute, Ewha Womans University, Seoul, South Korea
| | - Helena Knotkova
- MJHS Institute for Innovation in Palliative Care, New York, NY, USA,Department of Family and Social Medicine, Albert Einstein College of Medicine, The Bronx, NY, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - In-Uk Song
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Sang Hoon Lee
- Department of Radiology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea,Corresponding author.
| | - Yong-An Chung
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea,Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea,Corresponding author.
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166
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Wang A, Chen L, Jiang Y. Anodal Occipital Transcranial Direct Current Stimulation Enhances Perceived Visual Size Illusions. J Cogn Neurosci 2020; 33:528-535. [PMID: 33326330 DOI: 10.1162/jocn_a_01664] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Human early visual cortex has long been suggested to play a crucial role in context-dependent visual size perception through either lateral interaction or feedback projections from higher to lower visual areas. We investigated the causal contribution of early visual cortex to context-dependent visual size perception using the technique of transcranial direct current stimulation and two well-known size illusions (i.e., the Ebbinghaus and Ponzo illusions) and further elucidated the underlying mechanism that mediates the effect of transcranial direct current stimulation over early visual cortex. The results showed that the magnitudes of both size illusions were significantly increased by anodal stimulation relative to sham stimulation but left unaltered by cathodal stimulation. Moreover, the anodal effect persisted even when the central target and surrounding inducers of the Ebbinghaus configuration were presented to different eyes, with the effect lasting no more than 15 min. These findings provide compelling evidence that anodal occipital stimulation enhances the perceived visual size illusions, which is possibly mediated by weakening the suppressive function of the feedback connections from higher to lower visual areas. Moreover, the current study provides further support for the causal role of early visual cortex in the neural processing of context-dependent visual size perception.
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Affiliation(s)
- Anqi Wang
- Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University.,Key Laboratory of Brain and Cognitive Neuroscience, Dalian, China
| | - Lihong Chen
- Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University.,Key Laboratory of Brain and Cognitive Neuroscience, Dalian, China
| | - Yi Jiang
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Psychology, Chinese Academy of Sciences.,University of Chinese Academy of Sciences.,Chinese Institute for Brain Research, Beijing, China.,Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
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167
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Chen Q, Ke J, Cai X, Sun H, Chen Z, Li L, Su M, Fang Q. GABA-induced motor improvement following acute cerebral infarction. Am J Transl Res 2020; 12:7724-7736. [PMID: 33437357 PMCID: PMC7791484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 10/20/2020] [Indexed: 06/12/2023]
Abstract
γ-Aminobutyric acid (GABA) plays a key role in motor learning. In the aftermath of stroke, we monitored GABA+ content of primary motor cortex by magnetic resonance spectroscopy (MRS), assessing its relation to functional motor recovery following a standardized 4-week program of rehabilitation. The cohort included 20 patients, each experiencing stroke within 2 weeks of symptom onset. Twenty age-matched healthy subjects were also recruited as controls. GABA+ levels were determined at baseline and following rehabilitation, performed only once in sex- and age-matched control subjects. Motor functions were then measured via Fugl-Meyer Assessment (FMA). Processing of MRS data was driven by open-source Gannet software. Because GABA, macromolecules, and homocarnosine jointly contribute to MEscher-Garwood Point RESolved Spectroscopy (MEGA-PRESS) signals, the designation GABA+ (rather than GABA) was applied. Baseline GABA+/creatine (Cr) ratios proved significantly lower in patients with strokes than in control subjects (P<0.05). Following the 4-week rehabilitative regimen, significant improvement in FMA indices was evident across the test group. FMA scores and GABA+/Cr ratios correlated significantly at baseline, the GABA+/Cr ratio displaying a significant association with motor function (P=0.025). In the setting of acute stroke, GABA+/Cr ratios of primary motor cortex fell significantly below levels found in healthy subjects. The observed association between GABA+/Cr ratio and motor recovery underscores the utility of MRS-measured GABA as a key motor recuperative biomarker.
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Affiliation(s)
- Qingmei Chen
- Department of Neurology, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
- Department of Rehabilitation, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Jun Ke
- Department of Medical Imaging, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Xiuying Cai
- Department of Neurology, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Haiwei Sun
- Department of Emergency Medicine, The Second Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Zhiguo Chen
- Department of Neurology, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Li Li
- Department of Rehabilitation, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Min Su
- Department of Rehabilitation, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
| | - Qi Fang
- Department of Neurology, The First Affiliated Hospital of Soochow UniversitySuzhou 215000, Jiangsu Province, China
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168
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Pan D, Pan H, Zhang S, Yu H, Ding J, Ye Z, Hua T. Top-down influence affects the response adaptation of V1 neurons in cats. Brain Res Bull 2020; 167:89-98. [PMID: 33333174 DOI: 10.1016/j.brainresbull.2020.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/05/2020] [Accepted: 12/09/2020] [Indexed: 11/29/2022]
Abstract
The visual system lowers its perceptual sensitivity to a prolonged presentation of the same visual signal. This brain plasticity, called visual adaptation, is generally attributed to the response adaptation of neurons in the visual cortex. Although well-studied in the neurons of the primary visual cortex (V1), the contribution of high-level visual cortical regions to the response adaptation of V1 neurons is unclear. In the present study, we measured the response adaptation strength of V1 neurons before and after the top-down influence of the area 21a (A21a), a higher-order visual cortex homologous to the primate V4 area, was modulated with a noninvasive tool of transcranial direct current stimulation (tDCS). Our results showed that the response adaptation of V1 neurons enhanced significantly after applying anode (a-) tDCS in A21a when compared with that before a-tDCS, whereas the response adaptation of V1 neurons weakened after cathode (c-) tDCS relative to before c-tDCS in A21a. By contrast, sham (s-) tDCS in A21a had no significant impact on the response adaptation of V1 neurons. Further analysis indicated that a-tDCS in A21a significantly increased both the initial response (IR) of V1 neurons to the first several (five) trails of visual stimulation and the plateau response (PR) to the prolonged visual stimulation; the increase in PR was lower than in IR, which caused an enhancement in response adaptation. Conversely, c-tDCS significantly decreased both IR and PR of V1 neurons; the reduction in PR was smaller than in IR, which resulted in a weakness in response adaptation. Furthermore, the tDCS-induced changes of V1 neurons in response and response adaptation could recover after tDCS effect vanished, but did not occur after the neuronal activity in A21a was silenced by electrolytic lesions. These results suggest that the top-down influence of A21a may alter the response adaptation of V1 neurons through activation of local inhibitory circuitry, which enhances network inhibition in the V1 area upon an increased top-down input, weakens inhibition upon a decreased top-down input, and thus maintains homeostasis of V1 neurons in response to the long-presenting visual signals.
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Affiliation(s)
- Deng Pan
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China
| | - Huijun Pan
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China
| | - Shen Zhang
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China
| | - Hao Yu
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China
| | - Jian Ding
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China
| | - Zheng Ye
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China
| | - Tianmiao Hua
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China.
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169
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Rafique SA, Steeves JKE. Assessing differential effects of single and accelerated low-frequency rTMS to the visual cortex on GABA and glutamate concentrations. Brain Behav 2020; 10:e01845. [PMID: 32964685 PMCID: PMC7749615 DOI: 10.1002/brb3.1845] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND The application of repetitive transcranial magnetic stimulation (rTMS) for therapeutic use in visual-related disorders and its underlying mechanisms in the visual cortex is under-investigated. Additionally, there is little examination of rTMS adverse effects particularly with regards to visual and cognitive function. Neural plasticity is key in rehabilitation and recovery of function; thus, effective therapeutic strategies must be capable of modulating plasticity. Glutamate and γ-aminobutyric acid (GABA)-mediated changes in the balance between excitation and inhibition are prominent features in visual cortical plasticity. OBJECTIVES AND METHOD We investigated the effects of low-frequency (1 Hz) rTMS to the visual cortex on levels of neurotransmitters GABA and glutamate to determine the therapeutic potential of 1 Hz rTMS for visual-related disorders. Two rTMS regimes commonly used in clinical applications were investigated: participants received rTMS to the visual cortex either in a single 20-min session or five accelerated 20-min sessions (not previously investigated at the visual cortex). Proton (1H) magnetic resonance spectroscopy for in vivo quantification of GABA (assessed via GABA+) and glutamate (assessed via Glx) concentrations was performed pre- and post-rTMS. RESULTS GABA+ and Glx concentrations were unaltered following a single session of rTMS to the visual cortex. One day of accelerated rTMS significantly reduced GABA+ concentration for up to 24 hr, with levels returning to baseline by 1-week post-rTMS. Basic visual and cognitive function remained largely unchanged. CONCLUSION Accelerated 1 Hz rTMS to the visual cortex has greater potential for approaches targeting plasticity or in cases with altered GABAergic responses in visual disorders. Notably, these results provide preliminary insight into a critical window of plasticity with accelerated rTMS (e.g., 24 hr) in which adjunct therapies may offer better functional outcome. We describe detailed procedures to enable further exploration of these protocols.
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Affiliation(s)
- Sara A. Rafique
- Department of Psychology and Centre for Vision ResearchYork UniversityTorontoONCanada
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Motor cortical excitability behavior in chronic spinal cord injury neuropathic pain individuals submitted to transcranial direct current stimulation-case reports. Spinal Cord Ser Cases 2020; 6:101. [PMID: 33208726 DOI: 10.1038/s41394-020-00355-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/06/2020] [Accepted: 10/17/2020] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Increased excitability of the motor cortex through transcranial direct current stimulation (tDCS) has been described as a non-pharmacological strategy for the treatment of Spinal Cord Injury neuropathic pain (SCINP). It is also believed that the ability to enhance motor cortex excitability (MCE) could be impaired within chronic SCINP individuals. The following case reports describe the MCE behavior in individuals with chronic SCINP submitted to electrical non-invasive neuromodulation. CASE PRESENTATIONS This article reports 11 cases with chronic SCINP in which each individual was submitted to a 5-day pre-post MCE analysis in order to evaluate its behavior after the anodal tDCS sessions. All cases maintained ongoing pharmacological treatment. Four individuals have shown negative variation of the MCE, two of which reported pain intensity reduction. Three other individuals had MCE-positive variation along 5 days, from which only one reported a VAS 0.5 pain reduction after the 5th day of observation. The other four individuals did not present significant variation of the MCE. DISCUSSION The positive variation of MCE was significantly altered by adjunctive tDCS only in three individuals, though no clinically relevant reduction in pain intensity was reported among these participants. Key factors such as pain and injury duration, age, chronic medication use and underlying maladaptive neuroplasticity may influence responsiveness to brain stimulation within this population. These case reports try to add evidence for cautious recommendation of tDCS in chronic SCINP individuals and to the necessity of identifying groups of individuals that are most susceptible to neuromodulation.
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171
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Transcranial direct current stimulation (tDCS) over the auditory cortex modulates GABA and glutamate: a 7 T MR-spectroscopy study. Sci Rep 2020; 10:20111. [PMID: 33208867 PMCID: PMC7674467 DOI: 10.1038/s41598-020-77111-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 11/04/2020] [Indexed: 02/06/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) is one of the most prominent non-invasive electrical brain stimulation method to alter neuronal activity as well as behavioral processes in cognitive and perceptual domains. However, the exact mode of action of tDCS-related cortical alterations is still unclear as the results of tDCS studies often do not comply with the somatic doctrine assuming that anodal tDCS enhances while cathodal tDCS decreases neuronal excitability. Changes in the regional cortical neurotransmitter balance within the stimulated cortex, measured by excitatory and inhibitory neurotransmitter levels, have the potential to provide direct neurochemical underpinnings of tDCS effects. Here we assessed tDCS-induced modulations of the neurotransmitter concentrations in the human auditory cortex (AC) by using magnetic resonance spectroscopy (MRS) at ultra-high-field (7 T). We quantified inhibitory gamma-amino butyric (GABA) concentration and excitatory glutamate (Glu) and compared changes in the relative concentration of GABA to Glu before and after tDCS application. We found that both, anodal and cathodal tDCS significantly increased the relative concentration of GABA to Glu with individual temporal specificity. Our results offer novel insights for a potential neurochemical mechanism that underlies tDCS-induced alterations of AC processing.
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172
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Zacharopoulos G, Kadosh Cohen R. Predicting Working Memory Capacity Based on Glutamatergic Concentration and its Modulation of Functional Connectivity. Neuroscience 2020; 457:12-19. [PMID: 33212221 DOI: 10.1016/j.neuroscience.2020.10.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
Working memory (WM) capacity, the amount of information one can hold online in mind, has a central role in cognition. Previous electrophysiological and imaging studies revealed the pivotal role of persistent activity within parietal and frontal regions as the neural foundations underpinning WM capacity. The best candidate molecules determining persistent activity are the brain's major excitatory and inhibitory neurotransmitters, glutamate and gamma-aminobutyric acid (GABA), respectively. However, our knowledge of these neurophysiological determinants in forming WM capacity is still poor. Using magnetic resonance spectroscopy (MRS), we examined the contribution of glutamate and GABA within the left intraparietal sulcus (IPS) and the left inferior/middle frontal gyrus (FG) in tracking WM capacity. A positive association was found between glutamate within the left IPS and WM capacity. By utilising resting-state functional MRI, we identified a negative association between parieto-cingulate connectivity and WM capacity. Individual variation in parieto-cingulate connectivity was explained by glutamatergic concentration in the IPS. Moreover, we found that parieto-cingulate connectivity mediated the relationship between interparietal sulcus glutamate and WM capacity. This set of findings reveals a novel mechanistic insight by which glutamatergic concentration within the IPS shapes WM capacity via parieto-cingulate connectivity.
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Affiliation(s)
- George Zacharopoulos
- Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, UK.
| | - Roi Kadosh Cohen
- Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, UK
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173
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Pisano F, Caltagirone C, Incoccia C, Marangolo P. Spinal or cortical direct current stimulation: Which is the best? Evidence from apraxia of speech in post-stroke aphasia. Behav Brain Res 2020; 399:113019. [PMID: 33207242 DOI: 10.1016/j.bbr.2020.113019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 09/04/2020] [Accepted: 11/11/2020] [Indexed: 10/23/2022]
Abstract
To date, new advances in technology have already shown the effectiveness of non-invasive brain stimulation and, in particular, of transcranial direct current stimulation (tDCS), in enhancing language recovery in post-stroke aphasia. More recently, it has been suggested that the stimulation over the spinal cord improves the production of words associated to sensorimotor schemata, such as action verbs. Here, for the first time, we present evidence that transpinal direct current stimulation (tsDCS) combined with a language training is efficacious for the recovery from speech apraxia, a motor speech disorder which might co-occur with aphasia. In a randomized-double blind experiment, ten aphasics underwent five days of tsDCS with concomitant treatment for their articulatory deficits in two different conditions: anodal and sham. In all patients, language measures were collected before (T0), at the end (T5) and one week after the end of treatment (F/U). Results showed that only after anodal tsDCS patients exhibited a better accuracy in repeating the treated items. Moreover, these effects persisted at F/U and generalized to other oral language tasks (i.e. picture description, noun and verb naming, word repetition and reading). A further analysis, which compared the tsDCS results with those collected in a matched group of patients who underwent the same language treatment but combined with tDCS, revealed no differences between the two groups. Given the persistency and severity of articulatory deficits in aphasia and the ease of use of tsDCS, we believe that spinal stimulation might result a new innovative approach for language rehabilitation.
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Affiliation(s)
- Francesca Pisano
- Department of Humanities studies - University Federico II, Naples, Italy
| | | | | | - Paola Marangolo
- Department of Humanities studies - University Federico II, Naples, Italy; IRCCS Santa Lucia Foundation, Rome, Italy.
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174
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Individual Cerebral Blood Flow Responses to Transcranial Direct Current Stimulation at Various Intensities. Brain Sci 2020; 10:brainsci10110855. [PMID: 33202753 PMCID: PMC7697831 DOI: 10.3390/brainsci10110855] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/03/2020] [Accepted: 11/11/2020] [Indexed: 12/12/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) has been shown to alter cortical excitability. However, it is increasingly accepted that tDCS has high inter- and intra-subject response variability, which currently limits broad application and has prompted some to doubt if the current can reach the brain. This study reports individual cerebral blood flow responses in people with multiple sclerosis and neurologically healthy subjects that experienced 5 min of anodal tDCS at 1 mA, 2 mA, 3 mA, and 4 mA over either the dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex (M1). The most notable results indicated anticipated changes in regional cerebral blood flow (rCBF) in two regions of one DLPFC subject (2 mA condition), and expected changes in one M1 subject in the 2 mA and 4 mA conditions and in another M1 subject in the 2 mA condition. There were also changes contrary to the expected direction in one DLPFC subject and in two M1 subjects. These data suggest the effects of tDCS might be site-specific and highlight the high variability and individualized responses increasingly reported in tDCS literature. Future studies should use longer stimulation durations and image at various time points after stimulation cessation when exploring the effects of tDCS on cerebral blood flow (CBF).
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175
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Zeng H, Pacheco-Barrios K, Cao Y, Li Y, Zhang J, Yang C, Fregni F. Non-invasive neuromodulation effects on painful diabetic peripheral neuropathy: a systematic review and meta-analysis. Sci Rep 2020; 10:19184. [PMID: 33154432 PMCID: PMC7645738 DOI: 10.1038/s41598-020-75922-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 10/06/2020] [Indexed: 12/30/2022] Open
Abstract
Diabetic Peripheral Neuropathy (DPN) typically is accompanied by painful symptoms. Several therapeutic agents have been tried for symptomatic relief, but with varying results. The use of non-invasive neuromodulation (NINM) is a potential treatment option for DPN. The objective of our study is to evaluate NINM effects on pain rating and nerve conduction velocity in DPN patients. The search was carried out in seven databases until Aug 30th, 2019. Finally, twenty studies met the inclusion criteria. We found a significant reduction of pain scores by central NINMs (effect size [ES] = - 0.75, 95% CI = - 1.35 to - 0.14), but not by the overall peripheral techniques (electrical and electromagnetic) (ES = - 0.58, 95% CI = - 1.23 to 0.07). However, the subgroup of peripheral electrical NINMs reported a significant higher effect (ES = - 0.84, 95% CI = - 1.57 to - 0.11) compared to electromagnetic techniques (ES = 0.21; 95% CI = - 1.00 to 1.42, I2 = 95.3%) . Other subgroup analysis results show that NINMs effects are higher with intensive protocols and in populations with resistant symptoms or intolerance to analgesic medications. Besides, NINMs can increase motor nerves velocity (ES = 1.82; 95% CI = 1.47 to 2.17), and there were no effects on sensory nerves velocity (ES = 0.01, 95% CI = - 0.79 to 0.80). The results suggest that central and peripheral electrical NINMs could reduce neuropathic pain among DPN patients, without reported adverse events. Well-powered studies are needed to confirm that NINM techniques as an alternative effective and safe treatment option.
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Affiliation(s)
- Huiyan Zeng
- Department of Endocrinology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 261 Datong Road, Er Sha Island, Guangzhou, 510105, China
| | - Kevin Pacheco-Barrios
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, 96 13th Street, Charlestown, Boston, MA, USA
- Unidad de Investigación Para La Generación Y Síntesis de Evidencias en Salud, Vicerrectorado de Investigación, Universidad San Ignacio de Loyola, Lima, Peru
| | - Ying Cao
- Department of Endocrinology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Ying Li
- Department of Endocrinology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jinming Zhang
- Department of Endocrinology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 261 Datong Road, Er Sha Island, Guangzhou, 510105, China
| | - Caifeng Yang
- Department of Endocrinology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 261 Datong Road, Er Sha Island, Guangzhou, 510105, China.
| | - Felipe Fregni
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, 96 13th Street, Charlestown, Boston, MA, USA.
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176
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Umesawa Y, Matsushima K, Atsumi T, Kato T, Fukatsu R, Wada M, Ide M. Altered GABA Concentration in Brain Motor Area Is Associated with the Severity of Motor Disabilities in Individuals with Autism Spectrum Disorder. J Autism Dev Disord 2020; 50:2710-2722. [PMID: 31997060 PMCID: PMC7374467 DOI: 10.1007/s10803-020-04382-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Several motor disabilities accompanied with autism spectrum disorder (ASD) are widely known despite limited reports of underlying neural mechanisms. Gamma-aminobutyric acid (GABA) levels in the motor-related cortical areas modulate several motor performances in healthy participants. We hypothesized that abnormal GABA concentrations in the primary motor area (M1) and supplementary motor area (SMA) associate with different motor difficulties for ASD adolescents/adults. We found that increased GABA concentrations in M1 measured using 1H-magnetic resonance spectroscopy exhibited lower motor performance in tasks requiring increased muscle strength while lower GABA concentrations in SMA were associated with lower scores in tests measuring body coordination. The degrees of neural inhibition in the M1 and SMA regions would contribute to different dimensions of motor disabilities in autism.
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Affiliation(s)
- Yumi Umesawa
- Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan.
| | - Kanae Matsushima
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto-shi, Kyoto, Japan.,Kansai Medical University, Hirakata-shi, Osaka, Japan
| | - Takeshi Atsumi
- Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan.,Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan.,Department of Medical Physiology, Faculty of Medicine, Kyorin University, Mitaka-shi, Tokyo, Japan
| | - Toshihiro Kato
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto-shi, Kyoto, Japan
| | - Reiko Fukatsu
- Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan
| | - Makoto Wada
- Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan
| | - Masakazu Ide
- Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan.
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177
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The role of the left dorsolateral prefrontal cortex in attentional bias. Neuropsychologia 2020; 148:107631. [DOI: 10.1016/j.neuropsychologia.2020.107631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 11/22/2022]
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178
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Ghasemian-Shirvan E, Farnad L, Mosayebi-Samani M, Verstraelen S, Meesen RL, Kuo MF, Nitsche MA. Age-related differences of motor cortex plasticity in adults: A transcranial direct current stimulation study. Brain Stimul 2020; 13:1588-1599. [DOI: 10.1016/j.brs.2020.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 08/21/2020] [Accepted: 09/09/2020] [Indexed: 12/14/2022] Open
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179
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Jahshan C, Wynn JK, Roach BJ, Mathalon DH, Green MF. Effects of Transcranial Direct Current Stimulation on Visual Neuroplasticity in Schizophrenia. Clin EEG Neurosci 2020; 51:382-389. [PMID: 32463701 DOI: 10.1177/1550059420925697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
People with schizophrenia (SZ) exhibit visual processing abnormalities that affect their daily functioning and remediating these deficits might help to improve functioning. Transcranial direct current stimulation (tDCS) is a potential tool for perceptual enhancement for this purpose, though there are no reports of tDCS applied to visual cortex in SZ. In a within-subject, crossover design, we evaluated the effects of tDCS on visual processing in 27 SZ. All patients received anodal, cathodal, or sham stimulation over the central occipital region in 3 visits separated by 1 week. In each visit, a backward masking task and an electroencephalography measure of visual neuroplasticity were administered after tDCS. Neuroplasticity was assessed with visual evoked potentials before and after tetanizing visual high-frequency stimulation. Masking performance was significantly poorer in the anodal and cathodal conditions compared with sham. Both anodal and cathodal stimulation increased the amplitude of P1 but did not change the plasticity index. We found significant plasticity effects of tDCS for only one waveform for one stimulation condition (P2 for anodal tDCS) which did not survive correction for multiple comparisons. The reason for the lack of tDCS stimulation effects on plasticity may be because tDCS was not delivered simultaneously with the tetanizing visual stimulus. The present findings emphasize the need for more research on the relevant parameters for stimulation of visual processing regions in clinical populations.
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Affiliation(s)
- Carol Jahshan
- Mental Illness Research, Education and Clinical Center (MIRECC), VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Jonathan K Wynn
- Mental Illness Research, Education and Clinical Center (MIRECC), VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Brian J Roach
- San Francisco Department of Veterans Affairs Medical Center, San Francisco, CA, USA.,Department of Psychiatry, University of California, San Francisco, CA, USA
| | - Daniel H Mathalon
- San Francisco Department of Veterans Affairs Medical Center, San Francisco, CA, USA.,Department of Psychiatry, University of California, San Francisco, CA, USA
| | - Michael F Green
- Mental Illness Research, Education and Clinical Center (MIRECC), VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
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180
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Saldanha JS, Zortea M, Torres ILDS, Fregni F, Caumo W. Age as a Mediator of tDCS Effects on Pain: An Integrative Systematic Review and Meta-Analysis. Front Hum Neurosci 2020; 14:568306. [PMID: 33192397 PMCID: PMC7654216 DOI: 10.3389/fnhum.2020.568306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/22/2020] [Indexed: 12/25/2022] Open
Abstract
Introduction: The transcranial direct current stimulation (tDCS) is a neuromodulatory technique with the potential to decrease pain scores and to improve chronic pain treatment. Although age is an essential factor that might impact the tDCS effect, most studies are solely conducted in adults. Therefore, the age limitation presents a critical research gap in this field and can be shown by only a handful of studies that have included other age groups. To examine the evidence upon the tDCS effect on pain scores on children, adolescents, or elderly, and indirectly, to infer the age-dependent impact on tDCS effects, we conducted a systematic review and meta-analysis. Methods: A systematic review searching the following databases: PubMed, EMBASE, and Science Direct using the following search terms adapted according to MeSh or Entree: [(“Adolescent” OR “Children” OR “Elderly”) AND (“tDCS”) AND (“Pain” OR “Pain threshold”) AND (“dorsolateral prefrontal cortex” OR “Motor cortex)] up to April 20th, 2020. We retrieved 228 articles, 13 were included in the systematic review, and five studies with elderly subjects that had their outcomes assessed by pain score or pain threshold were included in the meta-analysis. Results: For the analysis of pain score, 96 individuals received active stimulation, and we found a favorable effect for active tDCS to reduce pain score compared to sham (P = 0.002). The standardized difference was −0.76 (CI 95% = −1.24 to −0.28). For the pain threshold, the analysis showed no significant difference between active and sham tDCS. We reviewed two studies with adolescents: one study using anodal tDCS over the prefrontal cortex reported a reduction in pain scores. However, the second study reported an increase in pain sensitivity for the dorsolateral prefrontal cortex (DLPFC) stimulation. Conclusion: Our findings suggest tDCS may reduce pain levels in the elderly group. Nevertheless, the small number of studies included in this review—and the considerable heterogeneity for clinical conditions and protocols of stimulation present—limits the support of tDCS use for pain treatment in elderly people. Larger studies on the tDCS effect on pain are needed to be conducted in elderly and adolescents, also evaluating different montages and electrical current intensity.
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Affiliation(s)
- Júlia Schirmer Saldanha
- Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Maxciel Zortea
- Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Iraci Lucena da Silva Torres
- Pharmacology of Pain and Neuromodulation: Pre-Clinical Investigations Research Group, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil
| | - Felipe Fregni
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Physics and Rehabilitation Department, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Wolnei Caumo
- Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Pain and Palliative Care Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
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181
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Barron HC. Neural inhibition for continual learning and memory. Curr Opin Neurobiol 2020; 67:85-94. [PMID: 33129012 PMCID: PMC7116367 DOI: 10.1016/j.conb.2020.09.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/14/2020] [Accepted: 09/16/2020] [Indexed: 11/28/2022]
Abstract
In humans, the concentration of cortical GABA decreases during learning. Inhibitory plasticity provides homeostatic control to restore network stability. Memories are held dormant unless latent inhibitory connections are unmasked. Cortical inhibition protects overlapping memories from interference. The emerging model suggests neural inhibition promotes continual learning.
Humans are able to continually learn new information and acquire skills that meet the demands of an ever-changing environment. Yet, this new learning does not necessarily occur at the expense of old memories. The specialised biological mechanisms that permit continual learning in humans and other mammals are not fully understood. Here I explore the possibility that neural inhibition plays an important role. I present recent findings from studies in humans that suggest inhibition regulates the stability of neural networks to gate cortical plasticity and memory retrieval. These studies use non-invasive methods to obtain an indirect measure of neural inhibition and corroborate comparable findings in animals. Together these studies reveal a model whereby neural inhibition protects memories from interference to permit continual learning. Neural inhibition may, therefore, play a critical role in the computations that underlie higher-order cognition and adaptive behaviour.
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Affiliation(s)
- Helen C Barron
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Mansfield Road, Oxford, OX1 3TH, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford, OX3 9DU, UK.
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182
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Johnstone A, Grigoras I, Petitet P, Capitão LP, Stagg CJ. A single, clinically relevant dose of the GABA B agonist baclofen impairs visuomotor learning. J Physiol 2020; 599:307-322. [PMID: 33085094 PMCID: PMC7611062 DOI: 10.1113/jp280378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/15/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Baclofen is a GABAB agonist prescribed as a treatment for spasticity in stroke, brain injury and multiple sclerosis patients, who are often undergoing concurrent motor rehabilitation. Decreasing GABAergic inhibition is a key feature of motor learning and so there is a possibility that GABA agonist drugs, such as baclofen, could impair these processes, potentially impacting rehabilitation. Here, we examined the effect of 10 mg of baclofen, in 20 young healthy individuals, and found that the drug impaired retention of visuomotor learning with no significant effect on motor sequence learning. Overall baclofen did not alter transcranial magnetic stimulation-measured GABAB inhibition, although the change in GABAB inhibition correlated with aspects of visuomotor learning retention. Further work is needed to investigate whether taking baclofen impacts motor rehabilitation in patients. ABSTRACT The GABAB agonist baclofen is taken daily as a treatment for spasticity by millions of stroke, brain injury and multiple sclerosis patients, many of whom are also undergoing motor rehabilitation. However, decreases in GABA are suggested to be a key feature of human motor learning, which raises questions about whether drugs increasing GABAergic activity may impair motor learning and rehabilitation. In this double-blind, placebo-controlled study, we investigated whether a single 10 mg dose of the GABAB agonist baclofen impaired motor sequence learning and visuomotor learning in 20 young healthy participants of both sexes. Participants trained on visuomotor and sequence learning tasks using their right hand. Transcranial magnetic stimulation (TMS) measures of corticospinal excitability, GABAA (short-interval intracortical inhibition, 2.5 ms) and GABAB (long-interval intracortical inhibition, 150 ms) receptor activation were recorded from left M1. Behaviourally, baclofen caused a significant reduction of visuomotor aftereffect (F1,137.8 = 6.133, P = 0.014) and retention (F1,130.7 = 4.138, P = 0.044), with no significant changes to sequence learning. There were no overall changes to TMS measured GABAergic inhibition with this low dose of baclofen. This result confirms the causal importance of GABAB inhibition in mediating visuomotor learning and suggests that chronic baclofen use could negatively impact aspects of motor rehabilitation.
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Affiliation(s)
- Ainslie Johnstone
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Psychiatry, OHBA, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.,Department of Clinical and Movement Neurosciences, Institute of Neurology, University College London, London, UK
| | - Ioana Grigoras
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Psychiatry, OHBA, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.,MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Pierre Petitet
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Experimental Psychology, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Liliana P Capitão
- Department of Psychiatry, University of Oxford, Oxford, UK.,Oxford Health NHS Foundation Trust, Oxford, UK
| | - Charlotte J Stagg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Psychiatry, OHBA, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.,MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
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183
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Pellegrini M, Zoghi M, Jaberzadeh S. Can genetic polymorphisms predict response variability to anodal transcranial direct current stimulation of the primary motor cortex? Eur J Neurosci 2020; 53:1569-1591. [PMID: 33048398 DOI: 10.1111/ejn.15002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 09/17/2020] [Accepted: 10/02/2020] [Indexed: 11/28/2022]
Abstract
Genetic mediation of cortical plasticity and the role genetic variants play in previously observed response variability to transcranial direct current stimulation (tDCS) have become important issues in the tDCS literature in recent years. This study investigated whether inter-individual variability to tDCS was in-part genetically mediated. In 61 healthy males, anodal-tDCS (a-tDCS) and sham-tDCS were administered to the primary motor cortex at 1 mA for 10-min via 6 × 4 cm active and 7 × 5 cm return electrodes. Twenty-five single-pulse transcranial magnetic stimulation (TMS) motor evoked potentials (MEP) were recorded to represent corticospinal excitability (CSE). Twenty-five paired-pulse MEPs were recorded with 3 ms inter-stimulus interval (ISI) to assess intracortical inhibition (ICI) via short-interval intracranial inhibition (SICI) and 10 ms ISI for intracortical facilitation (ICF). Saliva samples were tested for specific genetic polymorphisms in genes encoding for excitatory and inhibitory neuroreceptors. Individuals were sub-grouped based on a pre-determined threshold and via statistical cluster analysis. Two distinct subgroups were identified, increases in CSE following a-tDCS (i.e. Responders) and no increase or even reductions in CSE (i.e. Non-responders). No changes in ICI or ICF were reported. No relationships were reported between genetic polymorphisms in excitatory receptor genes and a-tDCS responders. An association was reported between a-tDCS responders and GABRA3 gene polymorphisms encoding for GABA-A receptors suggesting potential relationships between GABA-A receptor variations and capacity to undergo tDCS-induced cortical plasticity. In the largest tDCS study of its kind, this study presents an important step forward in determining the contribution genetic factors play in previously observed inter-individual variability to tDCS.
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Affiliation(s)
- Michael Pellegrini
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
| | - Maryam Zoghi
- Department of Rehabilitation, Nutrition and Sport, School of Allied Health, Discipline of Physiotherapy, La Trobe University, Melbourne, Australia
| | - Shapour Jaberzadeh
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
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184
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Madrid J, Benninger DH. Non-invasive brain stimulation for Parkinson's disease: Clinical evidence, latest concepts and future goals: A systematic review. J Neurosci Methods 2020; 347:108957. [PMID: 33017643 DOI: 10.1016/j.jneumeth.2020.108957] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 08/27/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022]
Abstract
Parkinson's disease (PD) is becoming a major public-health issue in an aging population. Available approaches to treat advanced PD still have limitations; new therapies are needed. The non-invasive brain stimulation (NIBS) may offer a complementary approach to treat advanced PD by personalized stimulation. Although NIBS is not as effective as the gold-standard levodopa, recent randomized controlled trials show promising outcomes in the treatment of PD symptoms. Nevertheless, only a few NIBS-stimulation paradigms have shown to improve PD's symptoms. Current clinical recommendations based on the level of evidence are reported in Table 1 through Table 3. Furthermore, novel technological advances hold promise and may soon enable the non-invasive stimulation of deeper brain structures for longer periods.
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Affiliation(s)
- Julian Madrid
- Service of Neurology, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
| | - David H Benninger
- Service of Neurology, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
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185
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Wu D, Li C, Liu N, Xu P, Xiao W. Visual motion perception improvements following direct current stimulation over V5 are dependent on initial performance. Exp Brain Res 2020; 238:2409-2416. [PMID: 32776173 DOI: 10.1007/s00221-020-05842-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/25/2020] [Indexed: 11/26/2022]
Abstract
Transcranial direct current stimulation (tDCS) can improve visual perception. However, the effect of tDCS on visual perception is largely variable, possibly due to individual differences in initial performance. The goal of the present study was to evaluate the dependency of visual motion perception improvements on initial performance. Twenty-eight observers were randomly divided into two groups. Anodal tDCS and sham stimulation were separately applied to V5 (1.5 mA, 20 min), while observers performed a coherent motion direction identification task. The results showed that compared to sham stimulation, anodal tDCS induced a significant improvement in motion perception that lasted at least 20 min. In addition, the degree of improvement was dependent on initial performance, with a greater improvement magnitude observed for those with poorer initial performance. These results may have implications for understanding the nature of the stimulation rule and for the use of a customised stimulation protocol to enhance tDCS efficiency in practical applications.
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Affiliation(s)
- Di Wu
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Chenxi Li
- Scholl of Nursing, Yueyang Vocational Technical College, Yueyang, China
| | - Na Liu
- Department of Nursing, Air Force Medical University, Xi'an, China
| | - Pengbo Xu
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Wei Xiao
- Department of Medical Psychology, Air Force Medical University, Xi'an, China.
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186
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Steel A, Mikkelsen M, Edden RAE, Robertson CE. Regional balance between glutamate+glutamine and GABA+ in the resting human brain. Neuroimage 2020; 220:117112. [PMID: 32619710 PMCID: PMC9652611 DOI: 10.1016/j.neuroimage.2020.117112] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/17/2020] [Accepted: 06/27/2020] [Indexed: 12/04/2022] Open
Abstract
Models of healthy brain function and psychiatric conditions assume that excitatory and inhibitory activity are balanced in the human brain at multiple spatial and temporal scales. In human neuroimaging, concentrations of the major excitatory (glutamate) and inhibitory (γ-aminobutyric acid, GABA) neurotransmitters are measured in vivo using magnetic resonance spectroscopy (MRS). However, despite the central importance of E/I balance to theories of brain function, a relationship between regional glutamate and GABA levels in the human brain has not been shown. We addressed this question in a large corpus of edited MRS data collected at 19 different sites (n = 220). Consistent with the notion of E/I balance, we found that levels of glutamate+glutamine (Glx) and GABA+ were highly correlated (R = 0.52, p = 2.86 x 10−14). This relationship held when controlling for site, scanner vendor, and demographics. Controlling for neurochemicals associated with neuronal density and metabolism (i.e. N-acetylaspartate and creatine) significantly reduced the correlation between GABA+ and Glx, suggesting that the levels of GABA+ and Glx may be critically linked to regional metabolism. These results are consistent with the notion that excitation and inhibition are balanced in the human brain.
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Affiliation(s)
- Adam Steel
- Department of Psychology and Brain Sciences, Dartmouth College, Hanover, NH, USA.
| | - Mark Mikkelsen
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Caroline E Robertson
- Department of Psychology and Brain Sciences, Dartmouth College, Hanover, NH, USA
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187
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Azarpaikan A, Torbati HRT, Sohrabi M, Boostani R, Ghoshoni M. Timing-Dependent Priming Effects of Anodal tDCS on Two-Hand Coordination. J PSYCHOPHYSIOL 2020. [DOI: 10.1027/0269-8803/a000250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract. The aim of study was to investigate the interaction of time of applying anodal transcranial direct current stimulation (tDCS) with motor learning using a two-hand coordination (THC) task. Sixty-four healthy participants were tested under four stimulation conditions: anodal tDCS a head of the motor task, anodal tDCS during the motor task, anodal tDCS following the motor task, and sham tDCS. Transcranial direct current stimulation (tDCS) stimulation was applied on cerebellum by using a weak direct current (15 min) of 1.5 mA generated by a battery and regulated by the drive stimulator. The results show that on-line learning increased in the anodal tDCS-during group ( p = .039). The anodal tDCS-after group relied more on off-line learning ( p = .05). The during-tDCS and after-tDCS groups achieved greater improvements in speed/accuracy than the before-tDCS and sham-tDCS groups. The cerebellar tDCS may play a significant role to speed up motor skill acquisition and improve motor skill accuracy.
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Affiliation(s)
- Atefeh Azarpaikan
- Department of Motor Behavior, Faculty of Physical Education and Sport Science, Ferdowsi University of Mashhad, Iran
| | - Hamid Reza Taherii Torbati
- Department of Motor Behavior, Faculty of Physical Education and Sport Science, Ferdowsi University of Mashhad, Iran
| | - Mehdi Sohrabi
- Department of Motor Behavior, Faculty of Physical Education and Sport Science, Ferdowsi University of Mashhad, Iran
| | - Reza Boostani
- Department of Neurology, Mashhad University of Medical Sciences, Iran
| | - Majid Ghoshoni
- Department of Medicine Engineering, Faculty of Engineering, Azad University of Mashhad, Iran
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188
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Hassanzahraee M, Nitsche MA, Zoghi M, Jaberzadeh S. Determination of anodal tDCS intensity threshold for reversal of corticospinal excitability: an investigation for induction of counter-regulatory mechanisms. Sci Rep 2020; 10:16108. [PMID: 32999375 PMCID: PMC7527486 DOI: 10.1038/s41598-020-72909-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/09/2020] [Indexed: 12/05/2022] Open
Abstract
Transcranial direct current stimulation is applied to modulate activity, and excitability of the brain. Basically, LTP-like plasticity is induced when anodal tDCS (a-tDCS) is applied over the primary motor cortex. However, it has been shown that specific parameters of a-tDCS can induce a plasticity reversal. We aimed to systematically assess the intensity threshold for reversal of the direction of plasticity induced by a-tDCS, monitored by corticospinal excitability (CSE), and explored mechanisms regulating this reversal. Fifteen healthy participants received a-tDCS in pseudo-random order for 26 min with four intensities of 0.3, 0.7, 1, and 1.5 mA. To measure CSE changes, single-pulse TMS was applied over the left M1, and motor evoked potentials of a contralateral hand muscle were recorded prior to a-tDCS, immediately and 30-min post-intervention. Paired-pulse TMS was used to evaluate intracortical excitation and inhibition. CSE increased significantly following a-tDCS with an intensity of 0.7 mA; however, the expected effect decreased and even reversed at intensities of 1 and 1.5 mA. ICF was significantly increased while SICI and LICI decreased at 0.7 mA. On the other hand, a significant decrease of ICF, but SICI and LICI enhancement was observed at intensities of 1, and 1.5 mA. The present findings show an intensity threshold of ≥ 1 mA for 26 min a-tDCS to reverse LTP- into LTD-like plasticity. It is suggested that increasing stimulation intensity, with constant stimulation duration, activates counter-regulatory mechanisms to prevent excessive brain excitation. Therefore, stimulation intensity and plasticity induced by a-tDCS might non-linearly correlate in scenarios with prolonged stimulation duration.
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Affiliation(s)
- Maryam Hassanzahraee
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia.
| | - Michael A Nitsche
- Department of Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany.,Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
| | - Maryam Zoghi
- Department of Rehabilitation, Nutrition and Sport, School of Allied Health, Discipline of Physiotherapy, La Trobe University, Melbourne, Australia
| | - Shapour Jaberzadeh
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
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189
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No Effect of Anodal tDCS on Verbal Episodic Memory Performance and Neurotransmitter Levels in Young and Elderly Participants. Neural Plast 2020; 2020:8896791. [PMID: 33029128 PMCID: PMC7528151 DOI: 10.1155/2020/8896791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/14/2020] [Accepted: 09/01/2020] [Indexed: 01/05/2023] Open
Abstract
Healthy ageing is accompanied by cognitive decline that affects episodic memory processes in particular. Studies showed that anodal transcranial direct current stimulation (tDCS) to the left dorsolateral prefrontal cortex (DLPFC) may counteract this cognitive deterioration by increasing excitability and inducing neuroplasticity in the targeted cortical region. While stimulation gains are more consistent in initial low performers, relying solely on behavioural measures to predict treatment benefits does not suffice for a reliable implementation of this method as a therapeutic option. Hence, an exploration of the underlying neurophysiological mechanisms regarding the differential stimulation effect is warranted. Glutamatergic metabolites (Glx) and γ-aminobutyric acid (GABA) are involved in learning and memory processes and can be influenced with tDCS; wherefore, they present themselves as potential biomarkers for tDCS-induced behavioural gains, which are affiliated with neuroplasticity processes. In the present randomized, double-blind, sham-controlled, crossover study, 33 healthy young and 22 elderly participants received anodal tDCS to their left DLPFC during the encoding phase of a verbal episodic memory task. Using MEGA-PRESS edited magnetic resonance spectroscopy (MRS), Glx and GABA levels were measured in the left DLPFC before and after the stimulation period. Further, we tested whether baseline performance and neurotransmitter levels predicted subsequent gains. No beneficial group effects of tDCS emerged in either verbal retrieval performances or neurotransmitter concentrations. Moreover, baseline performance levels did not predict stimulation-induced cognitive gains, nor did Glx or GABA levels. Nevertheless, exploratory analyses suggested a predictive value of the Glx : GABA ratio, with lower ratios at baseline indicating greater tDCS-related gains in delayed recall performance. This highlights the importance of further studies investigating neurophysiological mechanisms underlying previously observed stimulation-induced cognitive benefits and their respective interindividual heterogeneity.
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190
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Beltran Serrano G, Pooch Rodrigues L, Schein B, Zortea M, Torres ILS, Fregni F, Caumo W. The Hypnotic Analgesia Suggestion Mitigated the Effect of the Transcranial Direct Current Stimulation on the Descending Pain Modulatory System: A Proof of Concept Study. J Pain Res 2020; 13:2297-2311. [PMID: 32982393 PMCID: PMC7502396 DOI: 10.2147/jpr.s253747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/24/2020] [Indexed: 12/20/2022] Open
Abstract
Objective We evaluated whether active(a)-tDCS combined with hypnotic analgesia suggestion (HS) would be more effective than a single active(a)-tDCS, and/or sham-(s)-tDCS and s-tDCS/HS on the following outcomes: function of descending pain modulatory system (DPMS) during the conditioned pain modulation test (CPM-test) (primary outcome), heat pain threshold (HPT), heat pain tolerance (HPTo) and cold pressor test (CPT) (secondary outcomes). We also examined whether their effects are related to neuroplasticity state evaluated by serum brain-derived-neurotropic factor (BDNF). Materials and Methods Forty-eight females received one session of one of the four interventions (a-tDCS/HS, s-tDCS/HS, a-tDCS, and s-tDCS) in an incomplete randomized crossover sequence. The a-tDCS or s-tDCS was applied over the left dorsolateral prefrontal cortex (DLPFC) for 30 minutes at 2mA. Results A generalized linear model revealed a significant main effect for the intervention group (P <0.032). The delta-(Δ) pain score on the Numerical Pain Scale (NPS0-10) during CPM-test in the a-tDCS/HS group was -0.25 (0.43). The (Δ) pain score on NPS (0-10) during CPM-test in the other three groups was a-tDCS=-0.54 (0.41), HS -0.01 (0.41) and s-tDCS/HS=-0.19 (0.43). A-tDCS/HS intervention increased the CPT substantially compared to all other interventions. Also, higher baseline levels of BDNF were associated with a larger change in CPT and HPTo. Conclusion These findings indicate that the HS combined with a-tDCS mitigated the effect of the a-tDCS on the DPMS. The a-tDCS up-regulates the inhibition on DPMS, and the HS improved pain tolerance. And, together they enhanced the reaction time substantially upon the CPT. Clinical Trial Registration www.ClinicalTrials.gov, identifier NCT03744897.
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Affiliation(s)
- Gerardo Beltran Serrano
- Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation at Hospital De Clínicas De Porto Alegre (HCPA), Porto Alegre, Brazil.,Psychology Department, Universidad Catolica De Cuenca, UCACUE, Cuenca, Ecuador
| | - Laura Pooch Rodrigues
- Laboratory of Pain and Neuromodulation at Hospital De Clínicas De Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Bruno Schein
- Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation at Hospital De Clínicas De Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Maxciel Zortea
- Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation at Hospital De Clínicas De Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Iraci Lucenada Silva Torres
- Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil.,Department of Pharmacology, Institute of Health Sciences (ICBS), Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil.,Pharmacology of Pain and Neuromodulation: Pre-Clinical Investigations Research Group, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil
| | - Felipe Fregni
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | - Wolnei Caumo
- Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation at Hospital De Clínicas De Porto Alegre (HCPA), Porto Alegre, Brazil.,Pharmacology of Pain and Neuromodulation: Pre-Clinical Investigations Research Group, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil
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191
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Splittgerber M, Salvador R, Brauer H, Breitling-Ziegler C, Prehn-Kristensen A, Krauel K, Nowak R, Ruffini G, Moliadze V, Siniatchkin M. Individual Baseline Performance and Electrode Montage Impact on the Effects of Anodal tDCS Over the Left Dorsolateral Prefrontal Cortex. Front Hum Neurosci 2020; 14:349. [PMID: 33100989 PMCID: PMC7506510 DOI: 10.3389/fnhum.2020.00349] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 08/04/2020] [Indexed: 11/15/2022] Open
Abstract
Anodal transcranial direct current stimulation (tDCS), applied over the left dorsolateral prefrontal cortex (lDLPFC), can produce significant effects on working memory (WM) performance and associated neurophysiological activity. However, results from previous studies are inconsistent and occasionally contradictory. This inconsistency may be attributed to methodological and individual differences during experiments. This study therefore investigated two hypotheses: (1) A multichannel-optimized montage was expected to be more effective than a classical bipolar montage, because of increased focality. (2) The subjects were expected to benefit differently from the stimulation depending on their initial task performance. In a sham-controlled crossover study, 24 healthy participants received bipolar, multichannel, and sham stimulation for 20 min in randomized order, targeting the lDLPFC while performing a 2-back WM task. After stimulation, electroencephalography (EEG) was recorded at rest and during 2-back and nontarget continuous performance task (CPT) performance. Bipolar and multichannel stimulations were both well tolerated and effectively blinded. We found no effect of stimulation on behavioral performance or neuronal oscillations comparing the classical bipolar or multichannel montage with sham stimulation. We did, however, find an interaction between stimulation and initial task performance. For multichannel stimulation, initially low-performing participants tended to improve their WM performance while initially high-performing participants tended to worsen their performance compared to sham stimulation. Both tDCS montages induced changes in neural oscillatory power, which correlated with baseline performance. The worse the participants’ initial WM performance was, the more task-related theta power was induced by multichannel and bipolar stimulation. The same effect was observed for alpha power in the nontarget task following multichannel stimulation. Notably, we were not able to show a superiority of multichannel stimulation compared to bipolar stimulation. Still, comparing both montages with sham stimulation, multichannel stimulation led to stronger effects than bipolar stimulation. The current study highlights the importance of investigating different parameters with potential influence on tDCS effects in combination. Our results demonstrate how individual differences in cognitive performance and electrode montages influence effects of tDCS on neuropsychological performance. These findings support the idea of an individualized and optimized stimulation setting, potentially leading to increased tDCS effects.
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Affiliation(s)
- Maike Splittgerber
- Institute of Medical Psychology and Medical Sociology, University Medical Center-Schleswig Holstein, Kiel University, Kiel, Germany
| | | | - Hannah Brauer
- Department of Child and Adolescent Psychiatry, Center for Integrative Psychiatry Kiel, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Carolin Breitling-Ziegler
- Department of Child and Adolescent Psychiatry and Psychotherapy, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Alexander Prehn-Kristensen
- Department of Child and Adolescent Psychiatry, Center for Integrative Psychiatry Kiel, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Kerstin Krauel
- Department of Child and Adolescent Psychiatry and Psychotherapy, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | | | | | - Vera Moliadze
- Institute of Medical Psychology and Medical Sociology, University Medical Center-Schleswig Holstein, Kiel University, Kiel, Germany
| | - Michael Siniatchkin
- Institute of Medical Psychology and Medical Sociology, University Medical Center-Schleswig Holstein, Kiel University, Kiel, Germany.,Clinic for Child and Adolescent Psychiatry and Psychotherapy, Medical Center Bethel, Bielefeld, Germany
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192
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Pacheco-Barrios K, Cardenas-Rojas A, Thibaut A, Costa B, Ferreira I, Caumo W, Fregni F. Methods and strategies of tDCS for the treatment of pain: current status and future directions. Expert Rev Med Devices 2020; 17:879-898. [PMID: 32845195 PMCID: PMC7674241 DOI: 10.1080/17434440.2020.1816168] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 08/25/2020] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique that has been widely studied for the treatment of chronic pain. It is considered a promising and safe alternative pain therapy. Different targets have been tested, each having their own particular mechanisms for modulating pain perception. AREAS COVERED We discuss the current state of the art of tDCS to manage pain and future strategies to optimize tDCS' effects. Current strategies include primary motor cortex tDCS, prefrontal tDCS and tDCS combined with behavioral interventions while future strategies, on the other hand, include high-intensity tDCS, transcutaneous spinal direct current stimulation, cerebellar tDCS, home-based tDCS, and tDCS with extended number of sessions. EXPERT COMMENTARY It has been shown that the stimulation of the prefrontal and primary motor cortex is efficient for pain reduction while a few other new strategies, such as high-intensity tDCS and network-based tDCS, are believed to induce strong neuroplastic effects, although the underlying neural mechanisms still need to be fully uncovered. Hence, conventional tDCS approaches demonstrated promising effects to manage pain and new strategies are under development to enhance tDCS effects and make this approach more easily available by using, for instance, home-based devices.
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Affiliation(s)
- Kevin Pacheco-Barrios
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, Massachusetts, USA
- Universidad San Ignacio de Loyola, Vicerrectorado de Investigación, Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud. Lima, Peru
| | - Alejandra Cardenas-Rojas
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Aurore Thibaut
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, Massachusetts, USA
- Coma Science Group, GIGA Consciousness, University of Liege, Liège, Belgium
| | - Beatriz Costa
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Isadora Ferreira
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Wolnei Caumo
- Pain and Palliative Care Service at Hospital de Clínicas de Porto Alegre (HCPA), Laboratory of Pain and Neuromodulation at UFRGS, Porto Alegre, Brazil
| | - Felipe Fregni
- Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, Massachusetts, USA
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193
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Mosayebi-Samani M, Melo L, Agboada D, Nitsche MA, Kuo MF. Ca2+ channel dynamics explain the nonlinear neuroplasticity induction by cathodal transcranial direct current stimulation over the primary motor cortex. Eur Neuropsychopharmacol 2020; 38:63-72. [PMID: 32768154 DOI: 10.1016/j.euroneuro.2020.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 02/13/2020] [Accepted: 07/20/2020] [Indexed: 01/05/2023]
Abstract
Transcranial direct current stimulation (tDCS) induces polarity-dependent neuroplasticity: with conventional protocols, anodal tDCS results in excitability enhancement while cathodal stimulation reduces excitability. However, partially non-linear responses are observed with increased stimulation intensity and/or duration. Cathodal tDCS with 2 mA for 20 min reverses the excitability-diminishing plasticity induced by stimulation with 1 mA into excitation, while cathodal tDCS with 3 mA again results in excitability diminution. Since tDCS generates NMDA receptor-dependent neuroplasticity, such non-linearity could be explained by different levels of calcium concentration changes, which have been demonstrated in animal models to control for the directionality of plasticity. In this study, we tested the calcium dependency of non-linear cortical plasticity induced by cathodal tDCS in human subjects in a placebo controlled, double-blind and randomized design. The calcium channel blocker flunarizine was applied in low (2.5 mg), medium (5 mg) or high (10 mg) dosages before 20 min cathodal motor cortex tDCS with 3 mA in 12 young healthy subjects. After-effects of stimulation were monitored with TMS-induced motor evoked potentials (MEPs) until 2 h after stimulation. The results show that motor cortical excitability-diminishing after-effects of stimulation were unchanged, diminished, or converted to excitability enhancement with low, medium and high dosages of flunarizine. These results suggest a calcium-dependency of the directionality of tDCS-induced neuroplasticity, which may have relevant implications for future basic and clinical research.
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Affiliation(s)
- Mohsen Mosayebi-Samani
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystr. 67, 44139 Dortmund, Germany; Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany
| | - Lorena Melo
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystr. 67, 44139 Dortmund, Germany; International Graduate School of Neuroscience, IGSN, Ruhr University Bochum, Bochum, Germany
| | - Desmond Agboada
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystr. 67, 44139 Dortmund, Germany; International Graduate School of Neuroscience, IGSN, Ruhr University Bochum, Bochum, Germany
| | - Michael A Nitsche
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystr. 67, 44139 Dortmund, Germany; Department of Neurology, University Hospital Bergmannsheil, Bochum, Germany
| | - Min-Fang Kuo
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystr. 67, 44139 Dortmund, Germany.
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194
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King BR, Rumpf JJ, Heise KF, Veldman MP, Peeters R, Doyon J, Classen J, Albouy G, Swinnen SP. Lateralized effects of post-learning transcranial direct current stimulation on motor memory consolidation in older adults: An fMRI investigation. Neuroimage 2020; 223:117323. [PMID: 32882377 DOI: 10.1016/j.neuroimage.2020.117323] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/23/2020] [Accepted: 08/26/2020] [Indexed: 01/09/2023] Open
Abstract
Previous research has consistently demonstrated that older adults have difficulties transforming recently learned movements into robust, long-lasting memories (i.e., motor memory consolidation). One potential avenue to enhance consolidation in older individuals is the administration of transcranial direct current stimulation (tDCS) to task-relevant brain regions after initial learning. Although this approach has shown promise, the underlying cerebral correlates have yet to be revealed. Moreover, it is unknown whether the effects of tDCS are lateralized, an open question with implications for rehabilitative approaches following predominantly unilateral neurological injuries. In this research, healthy older adults completed a sequential motor task before and 6 h after receiving anodal or sham stimulation to right or left primary motor cortex (M1) while functional magnetic resonance images were acquired. Unexpectedly, anodal stimulation to right M1 following left-hand sequence learning significantly hindered consolidation as compared to a sham control, whereas no differences were observed with left M1 stimulation following right-hand learning. Impaired performance following right M1 stimulation was paralleled by sustained engagement of regions known to be critical for early learning stages, including the caudate nucleus and the premotor and parietal cortices. Thus, post-learning tDCS in older adults not only exerts heterogenous effects across the two hemispheres but can also disrupt ongoing memory processing.
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Affiliation(s)
- Bradley R King
- Department of Movement Sciences, KU Leuven, Leuven, Belgium; LBI - KU Leuven Brain Institute, Leuven, Belgium.
| | | | - Kirstin-Friederike Heise
- Department of Movement Sciences, KU Leuven, Leuven, Belgium; LBI - KU Leuven Brain Institute, Leuven, Belgium
| | - Menno P Veldman
- Department of Movement Sciences, KU Leuven, Leuven, Belgium; LBI - KU Leuven Brain Institute, Leuven, Belgium
| | - Ronald Peeters
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium; Department of Imaging and Pathology, Biomedical Sciences Group, Leuven, Belgium
| | - Julien Doyon
- McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Joseph Classen
- Department of Neurology, University of Leipzig, Leipzig, Germany
| | - Genevieve Albouy
- Department of Movement Sciences, KU Leuven, Leuven, Belgium; LBI - KU Leuven Brain Institute, Leuven, Belgium
| | - Stephan P Swinnen
- Department of Movement Sciences, KU Leuven, Leuven, Belgium; LBI - KU Leuven Brain Institute, Leuven, Belgium
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195
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McIntire LK, McKinley RA, Goodyear C, McIntire JP. The Effects of Anodal Transcranial Direct Current Stimulation on Sleep Time and Efficiency. Front Hum Neurosci 2020; 14:357. [PMID: 33192380 PMCID: PMC7481387 DOI: 10.3389/fnhum.2020.00357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/06/2020] [Indexed: 11/13/2022] Open
Abstract
A single session of anodal transcranial direct current stimulation (tDCS) has been shown to increase arousal in healthy participants for up to 24 h post-stimulation. However, little is known about the effects of tDCS on subsequent sleep in this population. Based on previous clinical studies, we hypothesized that anodal stimulation to the left dorsolateral prefrontal cortex (lDLPFC) would produce higher arousal with decreased sleep time and stimulation to the primary motor cortex (M1) would have the converse effect. Thirty-six active duty military were randomized into one of three groups (n = 12/group); active anodal tDCS over the lDLPFC, active anodal tDCS over left M1, or sham tDCS. Participants answered questionnaires 3 times a day and wore a wrist activity monitor (WAM) to measure sleep time and efficiency for 3 weeks. On weeks 2 and 3 (order counterbalance), participants received stimulation at 1800 h before 26 h of sustained wakefulness testing (sleep deprived) and at 1800 h without sleep deprivation (non-sleep deprived). There were no significant effects for the non-sleep deprived portion of testing. For the sleep deprived portion of testing, there were main effects of group and night on sleep time. The DLPFC group slept less than the other groups on the second and third night following stimulation. There is no negative effect on mood or sleep quality from a single dose of tDCS when participants have normal sleep patterns (i.e., non-sleep deprived portion of testing). The results suggest that stimulation may result in faster recovery from fatigue caused by acute periods of sleep deprivation, as their recovery sleep periods were less.
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Affiliation(s)
- Lindsey K McIntire
- Infoscitex, Inc., Wright-Patterson Air Force Base, Dayton, OH, United States
| | - R Andy McKinley
- Air Force Research Laboratory/Applied Neuroscience Branch, Wright-Patterson Air Force Base, Dayton, OH, United States
| | - Chuck Goodyear
- Infoscitex, Inc., Wright-Patterson Air Force Base, Dayton, OH, United States
| | - John P McIntire
- Air Force Research Laboratory/Security and Intelligence Branch, Wright-Patterson Air Force Base, Dayton, OH, United States
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196
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Marquardt L, Kusztrits I, Craven AR, Hugdahl K, Specht K, Hirnstein M. A multimodal study of the effects of tDCS on dorsolateral prefrontal and temporo-parietal areas during dichotic listening. Eur J Neurosci 2020; 53:449-459. [PMID: 32746504 DOI: 10.1111/ejn.14932] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 07/24/2020] [Indexed: 01/06/2023]
Abstract
The underlying neural mechanisms of transcranial direct current stimulation (tDCS), especially beyond the primary motor cortex, remain unclear. Several studies examined tDCS effects on either functional activity, neurotransmitters or behavior but few investigated those aspects together to reveal how the brain responds to tDCS. The objective is to elucidate the underlying mechanisms of tDCS using a multimodal approach that extends from behavioral to neurotransmitter levels of explanation. Thirty-two healthy participants performed an auditory dichotic listening task at two visits, one session with sham and one session with real tDCS (2 mA) while simultaneously undergoing functional magnetic resonance imaging (fMRI). The anode and cathode were placed over the left temporo-parietal cortex (TPC) and dorsolateral prefrontal cortex, respectively. Before and after simultaneous dichotic listening/fMRI/tDCS, combined glutamate and glutamine (Glx) and myo-inositol levels were assessed in the stimulated areas. While fMRI and dichotic listening showed expected functional activity and behavioral effects, neither method demonstrated differences between real and sham stimulation. Glx only showed a statistical trend towards higher levels after real tDCS in both stimulated brain areas. There were no significant correlations between behavior and Glx. Despite a reasonable sample size, electrical field strength, and replication of behavioral and functional activity results, tDCS had little to no effect on dichotic listening, Glx, and functional activity. The study emphasizes that findings about the underlying neural mechanisms of the primary motor cortex cannot simply be generalized to other brain areas. Particularly, the TPC might be less sensitive to tDCS. Moreover, the study demonstrates the general feasibility of multimodal approaches.
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Affiliation(s)
- Lynn Marquardt
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.,NORMENT Center of Excellence, University of Bergen, Haukeland University Hospital, Bergen, Norway
| | - Isabella Kusztrits
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.,NORMENT Center of Excellence, University of Bergen, Haukeland University Hospital, Bergen, Norway
| | - Alexander R Craven
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.,NORMENT Center of Excellence, University of Bergen, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway
| | - Kenneth Hugdahl
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.,NORMENT Center of Excellence, University of Bergen, Haukeland University Hospital, Bergen, Norway.,Department of Radiology, Haukeland University Hospital, Bergen, Norway.,Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Karsten Specht
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.,Mohn Medical and Imaging Visualization Centre, Haukeland University Hospital, Bergen, Norway.,Department of Education, UiT/The Arctic University of Norway, Tromsø, Norway
| | - Marco Hirnstein
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.,NORMENT Center of Excellence, University of Bergen, Haukeland University Hospital, Bergen, Norway
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197
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Chen TX, Yang CY, Willson G, Lin CC, Kuo SH. The Efficacy and Safety of Transcranial Direct Current Stimulation for Cerebellar Ataxia: a Systematic Review and Meta-Analysis. THE CEREBELLUM 2020; 20:124-133. [PMID: 32833224 PMCID: PMC7864859 DOI: 10.1007/s12311-020-01181-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background – A promising new approach, transcranial direct current stimulation (tDCS) has recently been used as a therapeutic modality for cerebellar ataxia. However, the strength of the conclusions drawn from individual studies in the current literature may be constrained by the small sample size of each trial. Methods – Following a systematic literature retrieval of studies, meta-analyses were conducted by pooling the standardized mean differences (SMDs) using random-effects models to assess the efficacy of tDCS on cerebellar ataxia, measured by standard clinical rating scales. Domain-specific effects of tDCS on gait and hand function were further evaluated based on 8-meter walk and 9-hole peg test performance times, respectively. To determine the safety of tDCS, the incidences of adverse effects were analyzed using risk differences. Results – Out of 293 citations, 5 randomized controlled trials involving a total of 72 participants with cerebellar ataxia were included. Meta-analysis indicated a 26.1% (p = 0.003) improvement in ataxia immediately after tDCS with sustained efficacy over months (28.2% improvement after 3 months, p = 0.04) when compared to sham stimulation. tDCS seems to be domain-specific as the current analysis suggested a positive effect on gait (16.3% improvement, p = 0.04), however failed to reveal differences for hand function (p = 0.10) with respect to sham. The incidence of adverse events in tDCS and sham groups was similar. Conclusion – tDCS is an effective intervention for mitigating ataxia symptoms with lasting results that can be sustained for months. This treatment shows preferential effects on gait ataxia and is relatively safe.
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Affiliation(s)
- Tiffany X Chen
- Department of Biomedical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurology, College of Physicians and Surgeons, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA
| | - Chen-Ya Yang
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA.,Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA.,Department of Physical Medicine and Rehabilitation, Taichung Veterans General Hospital, Chiayi and Wanqiao Branch, Chiayi, Taiwan
| | - Gloria Willson
- Augustus C. Long Health Sciences Library, Columbia University New York, New York, NY, USA
| | - Chih-Chun Lin
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA.,Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA. .,Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA.
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198
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Codella R, Alongi R, Filipas L, Luzi L. Ergogenic Effects of Bihemispheric Transcranial Direct Current Stimulation on Fitness: a Randomized Cross-over Trial. Int J Sports Med 2020; 42:66-73. [PMID: 32781476 DOI: 10.1055/a-1198-8525] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Several types of routines and methods have been experimented to gain neuromuscular advantages, in terms of exercise performance, in athletes and fitness enthusiasts. The aim of the present study was to evaluate the impact of biemispheric transcranial direct current stimulation on physical fitness indicators of healthy, physically active, men. In a randomized, single-blinded, crossover fashion, seventeen subjects (age: 30.9 ± 6.5 years, BMI: 24.8±3.1 kg/m2) underwent either stimulation or sham, prior to: vertical jump, sit & reach, and endurance running tests. Mixed repeated measures anova revealed a large main effect of stimulation for any of the three physical fitness measures. Stimulation determined increases of lower limb power (+ 5%), sit & reach amplitude (+ 9%) and endurance running capacity (+ 12%) with respect to sham condition (0.16<ηp2 < 0.41; p<0.05). Ratings-of-perceived-exertion, recorded at the end of each test session, did not change across all performances. However, in the stimulated-endurance protocol, an average lower rate-of-perceived-exertion at iso-time was inferred. A portable transcranial direct current stimulation headset could be a valuable ergogenic resource for individuals seeking to improve physical fitness in daily life or in athletic training.
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Affiliation(s)
- Roberto Codella
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy.,Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milan, Italy
| | - Rosario Alongi
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy
| | - Luca Filipas
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy.,Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milan, Italy
| | - Livio Luzi
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy.,Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milan, Italy
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199
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Galli G, Miniussi C, Pellicciari MC. Transcranial electric stimulation as a neural interface to gain insight on human brain functions: current knowledge and future perspective. Soc Cogn Affect Neurosci 2020; 17:4-14. [PMID: 32756871 DOI: 10.1093/scan/nsaa099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/12/2020] [Accepted: 07/11/2020] [Indexed: 11/12/2022] Open
Abstract
The use of brain-stimulation approaches in social and affective science has greatly increased over the last two decades. The interest in social factors has grown along with technological advances in brain research. Transcranial electric stimulation (tES) is a research tool that allows scientists to establish contributory causality between brain functioning and social behaviour, therefore deepening our understanding of the social mind. Preliminary evidence is also starting to demonstrate that tES, either alone or in combination with pharmacological or behavioural interventions, can alleviate the symptomatology of individuals with affective or social cognition disorders. This review offers an overview of the application of tES in the field of social and affective neuroscience. We discuss issues and challenges related to this application and suggest avenue for future basic and translational research.
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Affiliation(s)
- Giulia Galli
- Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames, KT1 2EE, United Kingdom
| | - Carlo Miniussi
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Corso Bettini, 31, 38068 Rovereto, TN Italy
| | - Maria Concetta Pellicciari
- UniCamillus - Saint Camillus International University of Health Sciences, via di Sant'Alessandro 8, 00131, Rome, Italy
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200
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Tamaki M, Wang Z, Barnes-Diana T, Guo D, Berard AV, Walsh E, Watanabe T, Sasaki Y. Complementary contributions of non-REM and REM sleep to visual learning. Nat Neurosci 2020; 23:1150-1156. [PMID: 32690968 PMCID: PMC7483793 DOI: 10.1038/s41593-020-0666-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 06/11/2020] [Indexed: 02/07/2023]
Abstract
Sleep is beneficial for learning. However, it remains unclear whether learning is facilitated by non-REM (NREM) sleep or by REM sleep, whether it results from plasticity increases or stabilization, and whether facilitation results from learning-specific processing. Here, we trained volunteers on a visual task, and measured the excitatory and inhibitory (E/I) balance in early visual areas during subsequent sleep as an index of plasticity. E/I balance increased during NREM sleep irrespective of whether pre-sleep learning occurred, but it was associated with post-sleep performance gains relative to pre-sleep performance. By contrast, E/I balance decreased during REM sleep but only after pre-sleep training, and the decrease was associated with stabilization of pre-sleep learning. These findings indicate that NREM sleep promotes plasticity, leading to performance gains independent of learning, while REM sleep decreases plasticity to stabilize learning in a learning-specific manner.
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Affiliation(s)
- Masako Tamaki
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.,National Institute of Occupational Safety and Health, Kawasaki, Japan
| | - Zhiyan Wang
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
| | - Tyler Barnes-Diana
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
| | - DeeAnn Guo
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Aaron V Berard
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
| | - Edward Walsh
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Takeo Watanabe
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
| | - Yuka Sasaki
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
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